Salami 1984.

Study characteristics
Methods	Allocation: randomised, but no further information Design: parallel‐group
Participants	Number: 30 randomised Age: mean 46 (SD 4) Gender: 17 M, 13 F Setting: Italy Eligibility criteria: Ménière's disease, clinically defined Exclusion criteria: other causes of vertigo Baseline characteristics: groups similar at baseline
Interventions	Betahistine 8 mg 3 times a day versus placebo over 6 weeks Intervention group: n = 15 Comparator group: n = 15 Use of additional interventions: none
Outcomes	Primary outcome: vertigo intensity on a 4‐point scale Secondary outcomes: vestibular function tests (electronystagmography and caloric testing)
Funding sources	Not stated
Declarations of interest	Not stated
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"Randomised"; no further information
Allocation concealment (selection bias)	Unclear risk	Method not stated
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Double‐blind, but no further information
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Double‐blind, but no further information
Incomplete outcome data (attrition bias) All outcomes	Low risk	No attrition (James 2001)
Selective reporting (reporting bias)	Low risk	Outcomes and adverse events reported
Other bias	Unclear risk	—

AAO‐HNS: American Academy of Otolaryngology – Head and Neck Surgery
BPPV: benign paroxysmal positional vertigo
CNS: central nervous system
ENG: electronystagmogram
ENT: ear, nose and throat
F: female
M: male
MD: Ménière's disease
MS: multiple sclerosis
SD: standard deviation